Common yarrow’s native propagation originated in the temperate regions of Asia and Europe, and it was introduced to North America during the colonial era. It is commonly seen growing across the United States in dry, disturbed soil, and while its beauty is delicate, the plant is also considered an aggressive weed. Common yarrow can be toxic to dogs, cats, and horses, yet poisoning is rare, as the tannins in the plant give it a bitter taste that deters animals from overconsumption.
Light
Yarrow prefers a garden plot that receives full sunlight, as these conditions will help it stay compact, yielding many blooms. This plant can tolerate partial shade, yet inadequate sunlight may cause it to grow long and spindly, requiring staking.
Soil
Common yarrow can adapt to a variety of soil compositions, from sandy, to loamy, to clay. Still, whatever the medium, this plant grows best in dry, well-drained conditions. Avoiding fertilizer or compost is often suggested, as nutrient-rich soil will encourage aggressive, and possibly unwanted, growth.
Water
Once established, common yarrow is drought-tolerant. Frequent, light waterings will only be needed to encourage germination and to mature small seedlings. After that, only a 1/2 inch of water weekly is needed to maintain growth. During periods of natural rainfall, cease watering altogether, especially if you’re getting up to, or more than, 1 inch of water per week.
Temperature and Humidity
Yarrow thrives in warm, summer conditions, with temperatures of 65 F to 75 F, but can start to suffer heat damage if temperatures rise over 86 F. And while generally considered easy-going, yarrow does not like cold drafts or temperatures near freezing. Yarrow can tolerate some humidity, but prefers conditions dry and may fall victim to root rot or fungus if its soil becomes saturated.
Fertilizer
Yarrow plants are low-maintenance when it comes to feeding. An annual side-dressing with compost in the spring should be enough to last throughout the season. However, some gardeners choose not to fertilize this plant at all, as nutrient-rich soil may encourage invasive spread.
Types of Common Yarrow
In the wild, yarrow typically blooms in lace-like shades of white or cream, but cultivated yarrow comes in many colors, like yellow, purple, pink, and red. Below are a few gardeners’ favorites:
‘Apple Blossom’ syn. ‘Apfelblute’ is cross between A. millefolium and A. taygetea. This variety features purplish-pink flower crowns that are 2 to 3 inches wide.‘Cerise Queen’ grows deep pink flowers and dark green foliage. The stalks of this cultivar reach 1 to 3 feet tall at maturity.‘Little Moonshine’ is a compact variety that only grows to 9 to 12 inches tall. It works well in containers and features bright yellow flowers and silvery-green leaves.The stalks of ‘New Vintage Red’ grow 12 to 15 inches tall and bear vibrant red flowers and bright green leaves.‘Paprika,’ a galaxy hybrid, grows brick-red flowers that are 2 to 3 inches wide with clusters of bright red flowers that eventually fade to shades of pink when the plant reaches maturity.
Pruning
Yarrow needs regular pruning and deadheading in order to keep the plant in a state of continual bloom. Plant stems can grow long in a hot, humid climate, and may require cutting after flowering to reduce plant height and to avoid flopping. Habitual pruning will also help keep the plant in check by preventing self-sowing.
Propagating Common Yarrow
In ideal growing conditions, yarrow spreads rapidly and sometimes aggressively. For this reason, it’s best to divide the plant every two to three years, or as needed. Propagating yarrow by division allows you to relocate the same variety to a different area of your garden, or you can gift it to friends looking for additions to their perennial beds. Here’s how to propagate yarrow through division:
How to Grow Common Yarrow From Seed
Yarrow also proliferates easily from seed sowed in the early spring. In approximately 120 days (three months), your plant will bear breathtaking blooms. Here’s how to plant yarrow from seed.
Potting and Repotting Common Yarrow
Common yarrow grows tall—some varieties can reach up to 40 inches. To accommodate its growth in containers, you’ll need to use a large pot or choose a dwarf variety. Yarrow grows best in a porous clay or terracotta pot that drains and dries easily. Any standard potting soil will do, but make sure it contains perlite for good drainage. It’s best to use plant starts when growing yarrow in pots, as you’ll get a jump on maturity and blooming. To do so, fill your pot with potting soil, dig several holes in the soil, and place a start in each one, allowing space in between. Water the pot thoroughly and allow it to drain, and then place it in a sunny patio location. Once established, make sure the soil drys out completely between waterings.
Overwintering
In late autumn, when the temperature starts to drop and your yarrow plant loses its vitality, cut the plant back to its basal leaves. The basal leaves will provide protection for the aboveground parts during the winter, and the act of pruning will allow the plant to focus on its root system during its period of dormancy.
Common Pests & Plant Diseases
Common yarrow may become susceptible to botrytis mold and powdery mildew—both of which will appear as a white powder on the leaves—if its roots are saturated with water. Improving soil conditions and airflow between the plants, as well as plenty of sunshine, can reduce the infection. Spittlebugs can also move into a patch of yarrow. This infestation will present as specks of “spit” on the plants. If the number of bugs becomes overwhelming, use a strong spray of water from the garden hose to reduce the population and to remove the coating from the bugs. This will expose the bugs to the sun, eventually killing them.
How to Get Common Yarrow to Bloom
Yarrow is a late bloomer, often showing its color in August in most growing regions. Ample sunlight and near-perfect soil conditions will assure a successful bloom. Once the plant starts blooming, constant deadheading will keep it in a continual state of color. Fertilization is not recommended to enhance yarrow blooms, but will only cause the plant to spread rapidly and produce more greenery.
Common Problems With Yarrow
Overwatering is the most common issue with this extremely drought tolerant plant, as roots soaked in water may rot, or fungus may move into the plant. To avoid this, always plant yarrow in well-drained soil and stick to the suggested watering schedule. Avoid watering this plant altogether during periods of rain. When grown in gardens without direct sun, yarrow stalks may become long and need staking. That said, it is next to impossible to stake a proliferate patch of yarrow. In that instance, all you can do is let it flop to the ground.
